Cyclized rubber containing basic amino polymers



crcuzm amen. conrammc nasrc ammo-rormaas William m climb, Buflalo, N. r., assirnor to E. I. du Pont de Nemonrs it Company, Wilmington, Del, a corporation of Delaware No Drawing. Application Augnst'23, 1941,

Serial No. 408,069

15 Claims. (oi. 260-134) This invention relates to condensation derivatives of rubber, especially to a means of prolonging their utility. More particularly, itnppertains to the incorporation of amino polymers in cyclized rubber, and its compositions, to extend their serviceableness.

A resin known as cyclized rubber is obtained I when a very high grade of low protein content rubber is made into a heavy viscous, non-drying cement with benzene, and refluxed with a catalyst such as stannic chloride. It appears to have the formula:

point, solution viscosity) of the cyclized rubber,

obtained by varying the time of reaction, result in a family of resins.

Cyclized rubber is of interest in many fields, for example, as a cementing agent in coating I compositions, as the principal component of adhesive compositions, etc. Adhesive bonds. de-

rubber and its'compositions, the preparation of heat, age and oxidation-resistant adhesives and transparent coating compositions, and the manufacture of adhesives having outstanding power to adhere plain and moistureproofed regenerated cellulose, plain and wax impregnated paper, and like materials. A general advance in the art, and other objects which will appear hereinafter, are also contemplated.

It has now been found that color formation in cyclized rubber can be restrained (avoided, eliminated, prevented, inhibited, curbed, repressed, obviated) and such products and compositions containingthe same stabilized and their useful life very greatly lengthened, by diluting (compending principally upon cyclized rubber (cyclized rubber alone or in combination with conventional adhesive materials) are initially very good, but they weaken rawdly, indicating that this material suffers some deleterious (presumably molecular) change with age. Cyclized rubber discolors, particularly when subjected to sunlight and/or heat. These drawbacks, inter alia, have retarded the commercial use of this material.

Originally it was assumed that the changes in properties of the cyclized rubber and compositions based thereon resulted from an oxidizing action, particularly under conditions involving light and heat, and efiorts were made to maintain such products in their initial condition by incorporating anti-oxidants therein. The slight extent of the improvement (in those cases where improvement could be detected) obtained by this scheme was discouraging. The time elapsing before loss of heat sealing properties increased less than five-fold. The results so far as discoloration was concerned were equally disappointing. Other undesirable features attendant upon these efforts were difliculties in the application of the compositions, objectionable lowering of the softening point of adhesive compositions, inability of the compounded material to withstand shock, etc.

It was, therefore, an object of this invention to stabilize cyclized rubber and compositions comprising the same. Other objects were to increase the utility and lengthen the useful life of cyclized pounding with, incorporating therein) them with certain amino polymers. The polymeric amino substances are mostly synthetic resins derived from ammonia and/or monomeric amino-hydrogen-containing bodies which are capable of being formed into coherent (self-sustaining) films, and which are substantially insoluble in water and soluble in 2% aqueous acetic acid and organic solvents. They are, with few exceptions, substantially insoluble in 5% aqueous ammonia or sodium hydroxide. The amino nitrogen may be primary, secondary or tertiary, and may be part of an open chain or of a cyclic molecular structure.

Comparative heat seal strengths appear to be the most satisfactory way of showing the eifectiveness (stabilizing efl'ect) of the amino polymers. A standard heat 1 seal strength test (U. S. A. Patent No. 2,147,180 to Ubben) was used to secure that data in the following tables of rel resentative results.

The compositions tested consisted of 10 parts paraflin wax, parts cyclized rubber 1 and addition material (the percent of which, based on the amount of parailin wax plus cyclized rubber, is set out in the tabulation). The heat sealed regenerated cellulose test strips were aged at F. (35 C.) for the time set out in the tabulation at the tops of the'columns of heat seal strengths.

exo prep eration reaction had subsided. It had a deformation point I drownln the reaction mass before the initial exothermic 2 2,sso,aes

Table I! Hsstssalsisength PG! d a Btsbiiiser Dsys sging Y 1 14 n as so 4:

None control M 50 I) l0 l0 10 h l thacr lste monomer 200 06 c i0 i0 l0 l0 2 %."..m.... .m- I :2: 1:: 1:: 1:: .52 ea ""4331--- y m m soo :00 180 no 180 """".m" ino fi"1""1ii&ii3i5"'i me 323 323 '32 me I i --W'-'-""-' .1... Te 1,... e a e is :52

00 me scrys l 1 g"... ryde-mzthyl-smine MK? 210 110 140 no 140 140 130 .....-.---do 200 110 m 100 no no we Diphen eme-(ma h d mm 1: 2% m m "iiii' "iii 6 Y O tn" rhsnol-i o nnsldehydo-piperuinereeln 200 175 100 160 150 150 a a. 186 us no so mo s do :00 me no no 190 no s...., phthslsteresin 300 1165 it! 156 140 136 smabotdths'monomerbsminobodhshincludediorpurposesoioomparhoa.

The compositions tested consisted of 10 parts The compositions tested consisted of 10 parts parailln wax, parts cyclized rubber and the paramn .wax, 90 parts Marbon B and 3 parts addition materials set out inthe tabulation. The 26 of addition material. The heat sealed regenheat sealed regenerated cellulose test strips were erated-eellulose' test strips were aged at F.

aged at 'flfi' I. (35' C.) for-the time indicated. (359(1) tor the time set. out in the tabulation.

ram 111 .Ioersolsgisg P8 m Stabilize I V flunhinphours 4 s 1: 10 so mes etatro 5 s00 is m 8.4..- mmstsiylsmvnoethylmethmlstemonomer soc is 10 1-... Dimsthylsminoethylmethsnylste polymer :00 145 no so as a do :00 us no 15 so 1 an .soo 190 186 175 00 uninoethyl methserylste polymer no 180 10 3 thyhmineresim; :00 1so as 50 15 l M soc no 80 70 15 1 m dehydsreein W 33 :0: i3 9'3 l5 gusnidine-Iormal L lln no 118 106 80 00 00 s ,d. We"... 2: :2: as 2: :2

mush s do 9 I an 1! no 4s so 'Thseibstolthsmonomdeaminobodieshinclndediorpurpoasdeomm.

The compositions tested consisted of 10 pafls 50 How the foregoing objects and related endsparailn wax,-90 parts cyclized rubber and the addition materials set out in the tabulation. The regenerated cellulose test strips were exposed to a standard sun lamp for the time set out in the are accomplished will be apparent from the following exposition, in which are disclosed the principle and divers embodiments of the inventabulstion. 66 carrying out the same. Parts aregiven by weight Table IV throughout the application, unless otherwise specified. Heatsealstrength 3 M I c 1 sum Prepare a moistureprooilng coating composition (lacquer) by dissolvinga mixture of 90 parts;

insl Pliollte (unmill'ed material softening at 30'C.),. (110Qpartsparaillnwax(MP.60' c.) and lpart ethyl amino ethyl 'methacrylate polymer, inm fiarayr m 65 toluene. Pass a sheet oi regenerated cellulose 200 150 Ill approximately 0.00088 inch thick through a bath f m m m 150 15 of this composition remove the excess solution m u e -i s m m m, no from the surface; by means of doctor knives, and.

' introduce the coated sheet into a drier through I Idn m0 W 70 which air is. circulating; Raise the temperature Y H rapidly and dry the coating at a temperature llhe ame rubber used was the product resulting from g the non-homogeneous material obtained by wax The l a1 8 ced s my.

prepara in reaction had subsided. It hada deformation v I 1 52211 1 05 rod a havin oftening point 053;;- c im purlty site..." Emmi-mil" i l? ear and in m u s s ypresen :11 av s tion, including the best mode contemplated m approximately equal to the melting point of the ase ass parent, flexible, and moistureproof. and exhibits no degradation of moistureproofness or heat seal properties after a period of 7 days from the time .of coating.

Example I! Apply a moistureprooilng coating composition consisting of: PW Pliolite (softening point 80' C.) 00 Paramn wax (M. P. 60' C.) 10' Dimethyl amino ethyl methacrylate polymer..- 3

to a regenerated cellulose sheet in the manner described in Example I. A product so produced is highly transparent, moistureproof, and exhibits good heat seal with no degradation in these properties after the elapse of a considerable period of time.

Example 111 Apply a composition consisting of:

' Parts Plioiite (homogenized, softening point 30 C.) 90

Paramn wax (I. P. 60 0.) 1o Dimethyl amino ethyl methacrylate polymer.-

to a sheet of regenerated cellulose in the manner described in Example I. Moistureproofed sheets so produced exhibit good heat seal with no degradation over aperiod of six weeks from the time of coating.

Example IV Apply a composition consisting of:

Parts Pliolite (homogenized, softening point 30 C.) 90 Paraffin wax (M. P. 60 (2.) "gs-.. Diethyl amino ethyl methacrylate polymelfin 3 to a sheet of regenerated cellulose as described in Example I. A product so produced is highly transparent, flexible and moistureproof, and shows no degradation in these properties after a period ofpix weeks. In addition, after a two weeks interval the coating remains firmly adhesive upon the base sheet and cannot be loosened by immersion in water for a period of one hour or longer.

Example V Apply a composition. consisting of:

Parts Pliolite (homogenised, softening point 30 C.) 00 Parailln wax (H. P. 60 C.) 10 Diethyl amino ethyl methacrylate polymer.-- 5

to a sheet of regenerated cellulose as described in Example I. correspondingly excellent results are obtained.

Example VI Apply a composition consisting oi:

Parts Pliolite (homogenized, softening point 30'' C.) 90

Paramn wax (M. P. 60 C.) l0 Phenol formaldehyde methyl amine resin..--- 5 to a sheet of regenerated cellulose, as described in Example 1. Similar excellent results are obtained.

Example VII Dissolve a composition consisting of:

O Parts Pliolite (homogenized, softening point 30 C.) 90 Parailin wax (M. P. 60 C.) l0 Diphenyl guanidine formaldehyde resin 2 in toluene, and apply it to a regenerated cellulose sheet as described in Example 1. Similar excellent results are obtained.

Eaample m Dissolve a composition consisting of: PW Pliolite (homogenised, softening point 30 C.) 00 Paraffin wax (M. P. 60' C.) 10 Phenol formaldehyde piperaaine resin 8 in benzene and apply it to a regenerated cellulose sheet, as described in Example I. Similar excellent results are obtained.

Example IX Apply a composition consisting of:

Parts Pliolite (homogenised, softening point 30 C.) 00 Paramn wax (M. P. 00 C.) 10 Triethanol amine phthalate resin. 3

to a sheet of regenerated cellulose, in the manner described in Example I. Similar results are obtained.

Example X Dissolve a composition consisting of Parts Marbon B (softening point 50 C.).. 90 Paraffin wax (M. P. C.) 10

Dimethyl amino ethyl methacrylate polymer-- 3 in toluene, and apply it to a sheet of regenerated cellulose, as described in Example I. Similar excellent results are obtained.

Example x! Dissolve a composition consisting of:

Parts Marbon B (softening point 50 C.) Paraifln wax (M. P. 60 C.) 10 Phenol formaldehyde methyl amine resin 3 in toluene. and apply it to a sheet of regenerated cellulose, as described in Example I. Similar excellent results are obtained.

. Example XII Dissolve a composition consisting of:

Parts Marbon B (softening point 50 C.) 90 Paraffin wax (M. P. 80 C.) 10 Diphenyl guanidine formaldehyde resin---" 3 a O in toluene, and apply it to a sheet of regenerated cellulose as described in Example I. Similar excellent results were obtained.

Epample XIII Dissolve a composition consisting of:

Parts Marbon B (softening point 60 C.) 90 Paraflln wax (M. P. 60 C.) 10 Phenol formaldehyde piperazine resin 3 in toluene, and apply it to a sheet of regenerated cellulose, as described in Example I. Similar results are obtained.

Ezample XIV Dissolve a composition comprising essentially:

' Parts Pliolite (deformation point 65 C.) 90 Hydrogenated, methyl abietate 10 Dimethyl amino ethyl methacrylate polymer- 3 in toluene, and apply it to a surface of regenerated cellulose film. The coated illm, although not moistureproof, will be highly flexible and transparent and exhibits good heat seal bond strength for long periods of time.

-whieh the new combination is ei! Sample xv A batch of having a deformation point of 2'7'-80 C.) and phenol formaldehyde methyl amine resin (prepared'according to Example I of U. 8. A. Patent No. 2,098,889) mixture was prepared. The proportions were:

Parts Rubber condensation derivative 25 Amino polymer 6.2' Toluene 81.2

"The term "condensation" is used in the same sense that it is emploged by Cohen (page 245 of his "Organic Chemistry for A vanes fltudentsi lm edition}, namely: "Condensation may, then, be de ed as the u on of two or more organic molecules or parts of the same molecule with or w thout elimination of coin nent elements, in between carbon position omitting the amine polymer.

trample XVI Twenty-five (25) parts of the cyclized rubber )1 Example xv and 88 parts of phenol formaliehyde methyl amine resin prepared according to Example I of U. S. A. Patent No. 2,098,869,

cyclised rubber (a milled product.

were dissolved in 81.2 parts of toluene. Buliite paper (35 pound type) was coated with 0.002 to 0.003 inch of the resulting composition. The

coated paper was then aged at 65 0., and adhesive tests were made on samples at intervals of 3 to 5 days. It was 13 days before the-coated paper no longer adhered tenaciously to waxed shot gun shell paper stock.

trample XVII Prepare an adhesive composition containing cyclized rubber and amino polymer in the ratio of 80:20, by mixing 25 parts of Pliolite (softening point 80 0.) dissolved in '15 parts of toluene (with the aid of stirring), and 6.2 parts of polybeta-dimethyl amino ethyl methacrylate dissolved in 6.2 parts of toluene. Stir the mixture until homogeneous before utilization.

trample xvm Example XIX Prepare an adhesive composition containing cyclized rubber and amino polymer in the ratio of 80:20, bymixing 25 parts of Pliolite (softening point 30 C.) dissolved in parts of toluene (with the aid of stirring), and 6.2 parts of resinous reaction product of phenol, formaldehyde,

and methyl amine (prepared as described in Example I of U. S. A. Patent No. 2,098,869 to Harman and Meigs) dissolved in 8.2 parts of toluene.

Stir the mixture until homogeneous before utilization.

- Example I;

Dissolve 60 parts of cyclized rubber (Pliolite having a distortion point of 80' C.) by stirring it in 150 parts of toluene. To the resultant add 2.6 parts of the resinous reaction productci phenol, formaldehyde. and methyl amine (preparedasdescribedinIxampleIofU.8.A.Patent No. 2,098,669 to Harmon and Helga) dissolved in 5 parts of toluene. and mix the two solutions until homogeneous to produce an adhesive composition. v

Isamrle xx:

Prepare an adhesive composition by dissolving 50 parts of cyclised rubber (Pliolite having a softening point of 80 C.) in 150 parts of toluene, with stirring. To this add 5.5 parts of the resinous reaction product of diphenyi guanidine formaldehyde and methylamine dissolved in 10 parts of toluene. Stir the mixture until homogeneous before using. The ration of cyclized rubber to amino polymer in this composition is 90:10.

The amino polymer is prepared by passing 31 parts (1 mol) of methyl amine into 180 parts (2 mols) of 37% formaldehyde solution cooled with ice. The resultant solution of dimethylol methyl amine (1 mol) is then added to 215 parts (1 mol) of dlphenyl guanidine, and the mixture stirred for 15 minutes.- This dough-like product is allowed to stand for 22 hours to complete the reaction. At the end of this time the mixture becomes a hard. resinous mass. It is groimd under cold water, filtered, washed with water, and dried over calcium chloride in a vacuum dessicator to give a white powder soluble in acetone, ethyl acetate, chloroform, dioxan and toluene.

Example XXII Prepare an adhesive composition by dissolving 50 parts of cyclized rubber (Pliolite having a softening point of 55' C.) in 150 parts of toluene, with stirring. To this add 5.5 parts of the Example XXI resinous reaction product of diphenyl guanidine formaldehyde and methylamine dissolved in 10 parts of toluene. Stir the mixture until homogeneous before using. The ratio of cyclized rubber to amino polymer in this composition is 90:10.

Example xxm Prepare an. adhesive composition by dissolving 50 parts of cyclized rubber (Pliolite having a softening point of C.) in '150 parts of toluene, with stirring. To this add 5.5 parts of the Example XXI resinous reaction product of diphenyl guanidine formaldehyde and methylamine dissolved in 10 parts of toluene. Stir the mixture until homogeneous before using. The ratio of cyclized rubber to amino polymer in this composition is :10.

Example XXIV Prepare an adhesive composition by dissolving 50 parts of cyclized rubber (Plioform having a softening point of C.) in parts of toluene, with stirring. To this add 5.5 parts of the Example XXI resinous reaction productoi' diphenyl guanidine formaldehyde and methylamine dissolved in 10 parts of toluene. Stir the mixture until homogeneous before using. The ratio of cyclized rubber to amino polymer in this composition is 90:10.

Example XXV Example XXVI Prepare an adhesive composition by dissolving 50 parts of cyclized rubber (Plioiite having a softening point of 30 C.) in 150 parts of toluene,

with stirring. To this add 2.6 parts of diphenyl guanidine formaldehyde resin (prepared as described under group E of Harmon U. B. P. 2,- 300,367) dissolved in parts of toluene, and.,the

two solutions stirred until homogeneous. The

'ratio of the cyclized rubber to amine resin in this composition is 95:5.

Example XXVI] Prepare an adhesive composition by dissolving 8 parts of cyclized rubber (Plioiite having a softening pointof 30 C.) in 24 parts of toluene, with stirring. To this add 2 parts of n-butyi-diethanolamine dimethylol urea dimethyl ether resin (prepared as described under group 8 ct Harmon U. B. P. 2,300,367) dissolved in 20 parts of dioxan.

Example XXVI" Prepare an adhesive composition by dispersing 18 parts of cyclized rubber (Plioiite having a softening point of 30 C.) and 4 parts of dimethylol urea dimethyl ether-hexamethylene diamine resin (prepared as described under group R of Harmon U. S. P. 2,300,367) in 83 parts of toluene.

Example xxx:

Dissolve a highly molstureproof adhesive composition consisting of:

Cyclised rubber (Plioiite having a softening point of 30 0.)-.. 50 Hydrogenated methyl abietate 30 Paramn wax (60 C. M. P.) 20

Dicyclohexylaminoethyl methacrylate polymer in benzene (or toluene), apply the resultant to a This is accomplished by ball milling for 18 hours.

The ratio of cyclized rubber to resin is 4:1.

Bramble XXIX Dissolve a pressure sensitive adhesive composition consisting of:

Parts Cyclised rubber (Plioiite having a softening point of 30 C.) 45 Chlorinated dlilbenyl (62% chlorine) 40 Heavy mineral oil 5 Diethylaminoethyl methacrylate polymer... :0

in benzene (or toluene), apply the resultant to a surface, and allow the solvent to evaporate.

Example XXX Dissolve a pressure sensitive adhesive cmnposition consisting of:

in benzene (or toluene), apply the resultant to a surface, and allow the solvent to evaporate.

as plastic rubber derivative made by surface, and allow the solvent to evaporate.

Phenol-formaldehyde-methyl amine resin" 5 in benzene (or toluene) apply the resultant to a surface, and allow the solvent to evaporate.

Example XXX!!! mniistsolve a adhesive composition consistrun Cycllsed rubber (Plioiite having a softening point of 30 C.)

Polymerised isobutylene (liquid)--. 50

Dimethylaminoethyl methacrylaie polymer... 10

in benzene (or toluene), apply the resultant to a surface, and allow the solvent to evaporate.

In utilising the adhesive compositions, solutions are prepared according to the directions set out in the examples, and applied to a suitable backing (regenerated cellulose, coated regenerated cellulose, paper, leather, metal foil, and similar materials) by means of a brush, roller, doctor knife, etc., after which the solvent is allowedto evaporate. The deposited films are waterproof and flexible. They may or may not be adhesive in the dry condition and at ordinary temperatures. when moistened with bydrocarbon solvents such as toluene, or when sub- ,iected to heat and pressure, they have excellent adhesion to a wide variety of surfaces, including regenerated cellulose sheet, paper, metal foil, leather, wood, and the like. The adhesive films andbonds retain their heat sealing and adhesive properties for long periods of time.

The cyclized rubber may be premd in any one of several diilerent ways as disclosed. for example, in Mitchell U. S.- P. 2,321,704, and its composition and properties may vary somewhat, but however prepared, it is thermoplastic and less unsaturated than rubber. It appears to have an empirical formula (Cal-Is): and to be a condensation derivative of rubber. I

Condensation derivatives with a softening point from 50 to 140 C. are, in general, satisfactory for use in adhesives, lacquers. and the like. A product with a softening point-around C. is ordinarily employed. Obviously. the most satisfactory softening point for any particular use depends upon the nature of the use.

The cyclized rubber called Pliolite," menfloned in several of the examples, is a thermo- I ized bis-(4-ketocyclohexyl) by reacting cyclohexanone and methylamine: the resinous reaction product rubber with a catalyst of the tin tetrachloride -acid and insoluble in water which are suitable for purposes of this invention are those of groups A to Q inclusive disclosed in pp. 4, 5 and 6 of I Iarmon U. B. P. 2,300,367.

"Instead of simple polymers, interpolymers may be prepared, for instance, by reacting methyl methacrylate and methyl vinyl ketone in the presence of ammonium hydroxide or reacting beta-di-cyclohexylaminoethyl methacrylate montimer and beta-dimethylaminoethyl methacrylate monomer together under suitable conditions, or reacting dicyclohexylaminoethyl methacrylate with methyl vinyl ketone under suitable conditions. Other equivalent polymeric materials, such as copolymers, may also be used, provided their solubility characteristics are as previously set forth.

The two classes of basic amino-nitrogen-containing polymers which have given the most satisfactory results are the polymeric amino-alcohol esters of alpha-substituted acrylic acids described in U. S. A. Patents 2,138,762 (Harmon) and 2,138,763 (Graves), and the resins obtained by reacting phenols, formaldehyde and amines described in. U. S. A. Patent No. 2,098,869 (Harmon and Meigs).

The latter products, which are dilute acetic acid soluble resins, and with which may be classed the very satisfactory phenol formaldehyde piperazine resins, are obtained by reacting a phenol containing carbon, hydrogenand oxygen only, and having at least 2 unsubstituted nuclear positions ortho or para to the phenolic hydroxyl with formaldehyde and a non-aromatic primary amine containing less than 7 carbon atoms. A

"molecular ratio of amine to phenol of not less than 0.5:1 and not greater than 1:1, and a molecular ratio of aldehyde to amine not greater than 1:1 in this reaction, give especially desirethanolamine mono-methacrylate polymer; 2-

(diethylamino)-cyclohexyl methacrylate poly-v mer; 4-(beta-methacrylyloxyethyl) morpholine polymer; beta-di-methylaminoethyl methcrylate polymer; beta-diethylaminoethyl acrylate polymer; beta-dicycloheiwlaminoethyl acrylate polymer; l-(beta-methacrylyloxyethyl) piperidine polymer; the resin obtained by the hydrogenation, in the presence of ammonia, of polymerdimethylmethane; the resin obtained from the hydrogenation in the presence of ammonia, of polymerized methylyinyl ketone; the reaction product of polymeric methyl alpha-methylvinyl ketone and cyclohexylamine; the reaction products of polymeric methylvinyl ketone and aqueous ammonia (or cyclohexylamine, ethylenediamine, hexamethyl- I enedia'mine, and the like); the resin obtained with formaldehyde of acetone with formaldehyde and butylamine;

and phenol-formaldehyde-hydrazine resin, cresol-formaldehyde-tetraethylenepentamin resin,

phenol formaldehyde ethylenediamine resin, 5 phenol-formaldehyde-dodecyl amine resin, phenol-formaldehyde-thiourea resin and cresolformaldehyde-melamine resin.

The polymeric basic amino nitrogen-containing substance may be introduced into the cyclized rubber, and compositions containing the same, in any desired manner. Ordinarily the incorporation is made by the use of a mutual solvent or by milling, but grinding, kneading, and other conventional mixing procedures are satisfactory. The choice of amino polymer to be used depends partly upon the solubility of the polymer, partly on the compatibility of the polymer with the cyclized rubber in solution, and partly on the special requirements of the specific composition (adhesive, moistureproofing lacquer, etc.) being manufactured, such as softening point, degree of surface tack, etc. In general, basic resins soluble in toluene or gasoline, compatible with cyclized rubberin solution and copable of imparting the longest possible storage life to the cyclized rubber after the application,

are preferred. One criterion of stabilizing power is the basicity of the resin, Judged by the per 1 The stabilizing effect of melamine polymer is roughly proportional to, the amount used with the cyclized rubber. The practical limits are from 0.005 to 1.0 part of amino polymer per part of cyclized rubber product. The improvement obtained by using amounts of amino polymer below the aforementioned lower limit is 4 detectable, but not great enough to be of practical value.

Variations in the proportions of the other ingredients of the stabilized composition are permissible.

In adhesive compositions, the most satisfactory results have been obtained when the amount of the amino polymer used equalled 0.5 to 50.0% of the cyclized rubber. In molstureprooilng coating compositions, the most satisfactory results have been obtained when the amount of amino polymer was 0.5% to 30%,'and preferably 1.0% to 10% of the cyclized rubber.

The moistureprooilng coating ordinarily employed is a continuous unbroken layer comprising essentially moistureprooilng material (material which does not dissolve more than an inflnitesimal amount of, if any, water), for example, a waxy (wax-like) substance such as high melting paraflln wax and organic solvent soluble.

formers. Generally the base film contains softening material, for example, glycerol, and the coating contains plasticiz'ing material, for example dibutyl phthalate, to increase flexibility.

To overcome any haziness which might result from some proportions and combinations of other components of the coating, transparentizing (blending, homogenizing) material, for example, resins and gums such as dammar and ester 75 gum, is ordinarily included.

ether and dimethyl assasss Other auxiliary ingredients are known to the moistureprooiing art,

Moistureproonng coating compositions may be converted into self-sustaining films having the solids composition set forth, by procedures well known in the art, and may be coated on nonfibrous surfaces other than regenerated cellulose, for example, albuminous material such as casein, gelatine, etc., organic solvent soluble materials such as ethyl cellulose, cellulose acetate, etc., waxed surfaces of shot shell waxed cardboard, and the like.

The adhesive compositions may be applied as solutions (used in a broad sense to include both true solutions and pseudo-solution, which latter are in reality colloidal suspensions) or melts without any solvent, or melts with reduced amounts of solvent.

Although base sheets may be similarly coated with the moistureproonng compositions, in the preferred procedures the moistureprooilng coating compositions are applied by passing the base sheet through a bath (solution) containing the coating, or by spraying the coating solution on the base. a

In forming solutions of the cyclized rubberamino polymer compositions, aliphatic, aromatic and chlorinated hydrocarbons are suitable. The preferred substances are benzene, toluene, xylene, tetrachlorethane, kerosene, and related products. Adhesive materials may be prepared by emulsifying a hydrocarbon solution of the adhesive composition in water containing a wetting agent, that is, a material which decreases the surface tension between the hydrocarbon solution and the water. Although a variety of wetting agents may be used, the water soluble salts of alkyl sulfates, in which the alkyl group contains more than 7 carbon atoms, are preferred. Certain organic liquids (solvents) such as acetone, dimethyl formamide and ethylene glycol monomethyl ether, may be used for the same purpose. The presence of the ethylene glycol monomethyl formamide are particularly desirable in adhesives for moistureproofed regenerated cellulose sheet wrapping material when the presence of a solvent capable of softening the moistureprooflng coating is desired.

In preparing the adhesive compositions, resins (natural, synthetic and semi-synthetic) may be incorporated as adiuvants or augmenting agents. The preferred materials of this character include rosin, hydrogenated rosin, hydrogenated rosin derivatives, ester gum, pitches, cumarone indene resins, alkyd (p lyhydrlc alcohol-polycarboxylic acid reaction product) ,resins, dammar, and the like. Such materials compound readily with the cyclized rubber. It will be understood that it is not always desirable to have a resin present. when the presence of resins is desirable, one or more ma be used.

Plastic zers (sometimes improperly referred to as softeners) may also be incorporated in the adhesive compositions when desired. The preferred materials of this type are dlbutyl phthalate, dicresyl phosphate, chlorinated paraflln, dixylyl ethane, chlorinated diphenyls, hydrogenated methyl abietate, di-ethyl-toluene sulfonamide, camphor, hydrocarbon oils, and the like. One or more of material of this character may be present in the adhesive composition, or material of this character may be omitted.

In case it is desired to change the appearance of the stabilized cyclized rubber composition, dyes and/or pigments may be incorporated.

Waxes, as well as natural and synthetic resins, etc., may be added to enhance the adhesive and other characteristics of the cyclized rubber compositions. One or more waxes (used generically to include waxy substances like parailin wax, as well as true waxes which are monohydric alcohol esters of higher fatty acids) may be employed, as desired.

For adhesive compositions containing part of cyclized rubber product, 0 to 75 parts of transparentizing material (preferably 10 to 40 parts) and 0 to '75 parts of plasticizing material (preferably 10 to 40 parts) are satisfactory. In moistureproofing coating compositions containing 100 parts of cyclized rubber product, 0 to 25 (preferably 0 to 10) parts of plasticizing material and 0 to 50 (preferably 0 to 25) parts of transparentizing material, are employed. Such proportions can be applied as melts or solutions.

Various methods of measuring the stabilizing effect of the amino polymer are possible. The heat seal bond strength appears to be the simplest and most satisfactory, both in normal use and in accelerated tests.

In the past great difilculty has been encountered in sealing regenerated cellulose and like sheet material, particularly the moistureproofed varieties. Vast research programs and unbelievable expenditures in testing show that the materials commonly accepted asadhesives were useless in this field. To date only a few materials which will accomplish this purpose at all satisfactorily, have been discovered, and these materials seem to bear no chemical or physical relation to each other. In the formation of envelopes, bags and various other articles from the moistureproofed sheet materials, it is necessary, in order to preserve the moistureproofness, that a good uniform adhesive contact be secured between the different portions of the article in its fabrication. This adhesive contact must be secured without destroying the moistureproof characteristics or substantially impairing the transparency at the place of adhesion. Ordinarily it is also essential that the adhesive should not penetrate into the interior of the sheet to such an extent that, it renders the coating on the opposite side of the sheet tacky, because if it does, it may impair the molstureproof qualities of the article, and in addition cause it to stick to other articles with which it may come into con- I tact.

The present discovery affords an excellent solution of the aforementioned problem, The thermoplastic adhesive compositions of this invention are suitable for sealing smooth (glass-like non-porous, non-fibrous cellulosic sheets and films (such as those of regenerated cellulose) whether they have a moisture-proofing coating composition or not. These compositions are also eminently suited for producing permanently tacky pressure-sensitive adhesive tapes or anchoring other adhesives in the formation of permanently tacky pressure-sensitive adhesive tapes and masking material when coated upon bases such as regenerated cellulose film.

The adhesive compositions of this invention have an application which is broader than the sealing or regenerated cellulose sheet material and moisture-proofed regenerated cellulose sheet material. For example, the adhesives are applicable toarticles formed of or contaiing cellulose acetate or cellulose nitrate, to plastics, to artificial leather, to photographic films, to novelties, and the like. The adhesives are alsocapable oi use in Joining various materials,-.such as paper, cardboard, cloth, metal foils, metal sheets and the like to regenerated cellulose and cellulose 'deriva-- tive surfaces. The adhesives of this invention are eminently suited for laminating purposes.

The adhesive compositions are particularly useful in the field of pressure-sensitive adhesives. As anchoring agents they affects more secure bond between a pressure-sensitive adhesive-of the Scotch tape" type and regenerated cellulose film base. This application of the present invention is one of the most promising so far discovered. The Scotch tape (arecently developed product) ordinarily comprises a ribbon or tape of transparent or translucent regenerated cellulose having on the surface thereof a permanently tacky pressure-sensitive adhesive. The uses of such a material are almost unlimited, although the employment as masking material and Joining tape probably constitutes the largest volume of use. These and many other uses of the material involve repeated application and-removal of the adhesive tape from the surface.

. For such a purpose it is highly desirable that the adhesive material adhere firmly to the base sheet, and in particular that it adhere more firmly to the base sheet than to the surface to which such a tape is appliedl'lhe anchoring effect of the compositions of this invention are especially notable in this respect. When the anchoring compositions of the present invention are employed, the adhesiive material can be completely removed from the surface to which the tape hasbeen applied, withthe result that econ omies such as re-use of, the tape and avoidance of cleaning the surface where the tape was applied,

are possible. when such tapes are stripped from the surfaces to-which they have been adhered,

there remains acomparatively clean surface free from The adhesive 'may be applied tothe regeneratedcellulose ribbon in the conventional manner.

The thickness of the. adhesive layer in the Scotch tape type product usually falls within the range of 0.001 to 0.01 of an inch. Thicker? layers may, of course, be used for special purand having thermoplastic properties, have the further advantage that they contribute to the adhesive properties of the cyclised rubber. In an actual 'case it has been'iound that a 25-fold improvement in 65 C. ageing life for cyclired rubber containing the amino polymers as compared with the unmodified cyclised rubber, was obtained. About a 5-fold improvement is all that can be expected when anti-oxidants such as those used in rubber are employed. 7

The adhesive compositions adhere firmly to smooth glass-like surfaces such as those of regenerated cellulose and like non-fibrous sheet material, even when the surface has a moistureproof coating. Their adhesive properties. par-. ticularly the length of time during which the adhesive composition is effective, are greatly improved, both in the thermoplastic and pressuresensitive types.

In the moistureproofing coating composition field the results are even more striking. The

moistureproofing compositions adhere tenaciousvly to regenerated cellulose and like surfaces over long periods of time, even in'the presence of liquid water or under conditions of high relative humidity, and the characteristics of the heat seal bonds (particularly strength) are outstanding. Furthermore, by virtue of their ingredients, such coating compositions are cheaper and more economical than'many of those used heretofore exe tensively. In addition. sheet material having good slip (surface characteristics enabling adiacent sheets in a stack to separate from each other), a desideratum in material for use on Moistureproofness, moistureproofing and moistureproof materialsand expressions are defined in U. S. A. Patent No. 2,147,180 (Ubben). In-the interest of brevity. the definitions are not repeated here. The terms and expressions related thereto and employed herein. are used in accordance with such definitions.

Adhesive compositions comprising primarily the stabilized cyclized rubber of this invention, can be used advantageously in the sealing of the closures of shotshells. The bond to the waxed here to smooth regenerated cellulose sheet by I atures. j Slight pressures, such as might be exertedby means of a thumb or finger, are consurface (paper) remains firm at the temperatures up to 120 1''. (49 C.) which are reached in rapid firing, and no deposit or residue remains which accumulates in the gun barrel.

So far as is known, no organic polymeric basic material of this type has n su ested before for the present purpose. In addition to arresting the deterioration of the cyelliied rubber system or composition for longer, periods of time, amino polymers of this class have the additional advantage of adding to the film-forming or plastic 60 characteristics of the composition in question. By "film-forming". is meant the capability of beingv formed into a coherent, solid film, dry to the touch. Y

Some discussion of the meaning and significance of the above restrictions on the stabilizing materials may. be desirable. The term polymeric" implies an amorphous, high molecular weight substance usually capable of being formed into a coherent film"; if the agent be polymeric, non-volatile and film-forming it is retained in the film for apprecidbly longer times and does not detract from the film-forming ability of the composition. vBy "basic" is meant an ability to form acid addition salts, and by amino-nitrogen meant a material which can be caused to adpressure alone at ordinary normal room temper- 1 .templated in this definition.

. 'By way of comparison, the adhesion to smooth l i surfaces obtained .with the cyclized rubber comi positionsof this invention is greatly superior I to that obtained with rubber, rubber derivatives such as chlorinated rubbers, synthetic rubbers I and their derivatives. Many of the advantages of the present inven tion. are believed. apparent from the foregoing part of the specification. The cyclized rubber is I stabilized for long periods of "time, if not indefinitely, and as aresult the compositions containf ing the same have their useful life extended many times ever, even under conditions involving high temperatures and/or strong light.

' {The degree of stability resulting from the in-' 1 corporation of the polymeric or resinous basic vamino nitrogen-containing bodies in .cyclized rubber-is much greater than can be obtained by I incorporating conventional. anti-oxidants. The

.amino polymers being film forming bynature 76 is meant the nitrogen of an amino group as opposed to that of nitro, amido, nitrile, etc., groups. It is a matter of simple test to determine if the agent is basic in character and contains aminonitrogen. In the large majority of cases, the materials from which the agent is synthesized are a definite indication whether or not it contains amino-nitrogen. It is sufficiently basic if it dissolves readily in dilute aqueous acetic acid. The qualification organic-solvent-soluble!' implies simple physical solution (i.e.,- without chemical reaction) to an appreciable extent in one or more types of solvents such as alcohols, hydrocarbons, ketones, esters, etc. Thus, methylaminophenol-formaldehyde resin, which is readily soluble.in a number of solvents, is suitable for use in the invention, whereas deacetylated chitin is not because it is insoluble in organic solvents.

As many apparently widely different embodiments of this invention may be made without departingfrom the spirit and scope thereof, it is to be understood that this invention is not limited to the specific embodiments thereof except as defined in the appended claims.

I claim:

1. Sheet material coated with cyclized rubber containing a minor proportion of amino polymer insoluble in water and soluble in organic solvents and 2% acetic acid.

2. As a new composition of matter, cyclized rubber containing a minor proportion of basic amino polymer capable of being formed into coherent solid films which are substantially insoluble in water and aqueous ammonia and soluble in 2% aqueous acetic acid and organic solvents.

3. Cyclized rubber compounded with 0.5%- 50% of non-volatile, coherent, self-sustaining, aim-forming, polymeric, organic, halogen-free, basic amino-nitrogen containing substance capable of being formed into coherent solid films which are substantially insoluble in water and 5% aqueous ammonia and soluble in 2% aqueous acetic acid and organic solvents 4. A composition comprising essentially cyclized rubber and polymeric phenol-formaldehyde-methyl-amine resin capable of being formed into coherent solid films which are substantially insoluble in water and 5% aqueous ammonia and soluble in 2% aqueous acetic acid and organic solvents, the amine polymer being present in an amount within the range 0.5% to 50% of the cyclized rubber.

5. As a new composition of matter, cyclized rubber having a deformation point in the range 30-105 C. compounded with a minor proportion of resinous highly polymeric basic amino-nitrogen-containing compound capable of :being formed into coherent solid films which are substantially insoluble in water and 5% aqueous ammonia and soluble in 2% aqueous acetic acid and organic solvents.

6. As a new composition of matter, rubber cyclized with tin tetrachloride containing a minor proportion of basic amino polymer capable of being formed into coherent solid films which are substantially insoluble in water and 5% aqueous ammonia and soluble in 2% aqueous acetic acid and organic solvents.

7. A thin, flexible sheet material comprising a film of a moistureproof composition, said moistureproof composition comprising essentially 3%-50% wax and cementing material therefor, said cementing material being cyclized rubber in which is incorporated 0.5% to 50% (based on the cyclized rubber) of basic amino polymer capable of being formed into coherent solid films which are substantially insoluble in water and 5% aqueous ammonia and soluble in 2% aqueous acetic acid and organic solvents.

8. A thin, flexible sheet material comprising a film of a moistureproof composition, said moistureproof composition comprising essentially 8% -50% wax and cementing material therefor,

said cementing material being cyclized rubber in which is incorporated 3% to 15% (based on the cyclized rubber) of basic amino polymer capable of being formed into coherent solid films which are substantially insoluble in water and 5% aqueous'ammonia and soluble in 2% aqueous acetic acid and organic solvents.

9. A moistureproofing lacquer comprising essentially 12% solids and an organic solvent therefor, said solids comprising essentially 3% to 50% moistureproofing wax and cyclized rubber containing 0.5% to 50% of basic amino polymercapable of being tormed into coherent solid films which are substantially insoluble in water and 5% aqueous ammonia and soluble in 2% aqueous acetic acid and organic solvents.

10. The process of lengthening the effectiveness of moistureproofing coatings containing cyclized rubber, which comprises incorporating therein basic amino polymer capable of being formed into coherent solid films which are substantially insoluble in water and 5% aqueous ammonia and soluble in 2% aqueous acetic acid and organic solvents.

11. An article of manufacture comprising a base formed of a sheet of flexible, non-moistureproof, non-fibrous and transparent material coated with a composition comprising a coherent, self-sustaining, film-forming substance and a moistureproofing wax in proportions and of a thickness to produce a transparent moistureproof product, said-film-forming substance being cyclized rubber and basic amino polymer capable of being formed into coherent solid films which are substantially insoluble in water and 5% aqueous ammonia and soluble in 2% aqueous acetic acid and organic solvents.

12. A moistureproofing coating composition comprising essentially wax, cyclized rubber and basic amino polymer capable of being formed into coherent solid films which are substantially insoluble in water and 5% aqueous ammonia and soluble in 2% aqueous acetic acid and organic solvents.

13. An article of manufacture suitable for use as a sheet wrapping material, comprising a base sheet or film of transparent regenerated cellulose having a transparent, moistureproof and flexible coating on each side thereof, the total thickness of the coatings on both sides being from 0.00001 to 0.00015 of an inch, each of said coatings comprising essentially a cementing agent of cyclized rubber and a basic amino polymer capable of being formed into coherent solid films which are substantially insoluble in water and 5% aqueous ammonia and soluble in' 2% aqueous. acetic acid and organic solvents.

14. A sheet wrapping material comprising a regenerated cellulose base film and amoistureproofing coating, said moistureproofing coating comprising essentially cyclized rubber having a deformation point of about 30 C. and a minor proportion of a film-former of basic amino polymer capable of being formed into coherent solid films which are substantially insoluble in water and 5% aqueous ammonia and soluble in 2% aqueous acetic acid and organic solvents, paramn wax moistureprooflng agent, blending agent and l fi i i e method of extending the useful life of moisture-resistant regenerated cellulose film comprising a, coating embodying cyclized rubber cementing agent, which comprises diluting said cyclized rubber with basic amino polymer capable or being formed into coherent solid films which are substantially insoluble in water and 5% aqueous ammonia and soluble in 2% aqueous acetic 5 acid and organic solvents.

WIILIAM HALE CHARCH.

CERTIFICATE OF commcnou. Patent No. 2,550,585- June 6, 191m.

WILLIAM HALE 03.4m

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page )4, sec- 0nd column, line 25, for the word ration read "ratio"; page 5, second column, line 61+ for I (($63 read --(C B page 7, first column, line 66, for dicresyl reed --tricresy l--; and second column, line 72, for "contaiing" reed "containingpage 8, first column, line 52, for adhesiive" read -adhesive--; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 8th day of August, A. D. 191m.

Leslie Frazer (Seal) Acting Commissioner of Patents. 

